The instant invention relates to crane testing equipment and specifically to a crane load-test gauge which may be used as a proof load-test for certifying the lifting ability of a crane.
Heavy lift cranes must be certified as being capable of lifting an object having a weight up to a particular known maximum. The most frequent technique for conducting such testing involves lifting by a crane of a number of large concrete blocks of a known weight.
There are several disadvantages encountered in the proof testing of cranes through the use of concrete blocks. First, the blocks must be transported between crane locations. Cranes requiring certification are generally capable of lifting in excess of 100,000 pounds. Testing using concrete blocks requires either the shipment of an inordinate amount of weight, or the rigging of a crane such that a lighter weight will simulate a heavier weight under actual operating conditions. Second, although a block may have a known weight, repeated use frequently results in portions of the block being broken away, resulting in an actual weight less than that of the originally constructed block. Finally, if the crane being proof tested is equipped with twist-lock lift fittings, as are found on shipping containers, the crane must be rerigged with a lifting hook and bridle arrangement to accommodate the large concrete blocks.
An object of the instant invention is to provide a crane load-test gauge which is suitable for efficiently proof testing heavy lift cranes.
Another object of the instant invention is to provide a crane load-test gauge which is suitable for testing cranes equipped with both twist-lock and hook connections.
A further object of the instant invention is to provide a crane load-test gauge which is easily transportable in a relatively lightweight condition.
Another object of the instant invention is to provide a crane load-test gauge which is operable to simulate various sized containers.
Still another object of the instant invention is to provide a crane load-test gauge which has an adjustable gross weight.
The crane load-test gauge of the instant invention includes an elongate vessel having multiple fluid containing compartments therein. Each compartment has an open top side. A fluid carrying manifold is disposed along the length of the vessel and has a valve mechanism associated with each of the compartments for introducing fluid into the compartment. The manifold has a conventional fire hose connector on the free end thereof. A level adjusting mechanism is provided for adjusting the level of fluid in a compartment. The level adjusting mechanism includes a trim valve for partially emptying a single compartment and a sluice valve for transferring fluid between compartments. A sight gauge is affixed to a side of each compartment in communication with the interior thereof. The sight gauge is operable to indicate a fluid level in its associated compartment. A weight indicator includes calibrated markings adjacent each of the sight gauges to provide, with the fluid level at a predetermined point, the weight of the compartment and the fluid contained therein. An overflow mechanism is provided to prevent filling of the vessel beyond a predetermined level. A drain is provided for emptying completely the fluid contained in the vessel. The gauge includes a lifting mechanism for attaching the gauge to a crane to be proof tested.
These and other objects and advantages of the instant invention will become more fully apparent as the description which follows is read in conjunction with the drawings.